Leather-working machine



Dec. 11, 1928.

o. BOTTGER LEATHER wonxme MACHINE Filed Jan. 21, 1925' In zrn 202".

Patented Dec. ll, i228.

FTEfs OSKAR IBGTTGER, 0F FRANKFORT-ON-THE-IVIAIN, GERMANY, ASSIGNOR TO THE TUR- NEE TANNIHG- MACHINERY CQMPANY, OF PORTLAND, MAINE, A CORPORATION OF MAINE.

LEATHER-WORKING MACHINE.

Application filed January 21, 1925, Serial No. 3,798, and in Germany March 1, 1924.

This invention relates to leather working machines and more particularly to means for supporting the work as it is subjected to the action of an operating tool, such for example as a bulfing roll. I

One type of bufing machine employed in the manufacture of leather has three principal uses, namely :removing scratches and other imperfections from hides and skins of poor grain by snuffing off this defective surface, snuffing the grain side of leather so that a finishing liquid will penetrate more read ily and, in embossed leathers, to produce a two-tone effect. This type of machine includes a rapidly rotating buffing roll against which a piece of leather, held in the hands of the operator, is pressed by a bed roll which is movable toward and from the bufing roll under the control of the foot of the operator. Ordinarily the bed roll supports a bolster of felt or other yielding material which is subject to considerable wear and, therefore, requires frequent replacement.

An object of the present invention is to provide a leather working machineof the type just referred to with an improved support for the work.

With this object in view, this invention, in one aspect, comprises a leather working machine having a work support, or bolster, in the form of an endless band or belt of felt, or other material having a yielding surface, and a pair of supports for the band. In the illustrated embodiment of the invention, an

endless felt band is carried by a bed roll and by a tension roll, the bed roll being located in proximity to the buffing roll and the entire structure comprising the band and its supporting rolls being movable toward I and away from the buifing roll. Preferably, also, means is provided whereby the bed and-tension rolls may be relatively moved to maintain the desired tension of the band.

The invention also comprises particular combinations and arrangements of parts which will now be described in connection with the accompanying drawings illustrating a preferred embodiment of the invention and will then be set forth in the appended claims.

In the drawings: 7

Fig. l is a View in side elevation of a leather buffingmachine embodying the invention, a part of the frame being broken away to show the swing frame and its associated parts;

Fig. 2'is a similar view on a somewhat plan view. of the parts shown in or cylinder provided with a covering 4 of emery paper or sand paper or other abrasive. This roll is carried vbya shaft 6 supported in a frame 8 and is driven at relatively high speed, in the direction indicated by the arrow, by a pulley 10 and a belt 12, all as is common in this art. 7

The work L, such as a sheep skin, a calf skin or a side of leather, is supported by a bolster 14 in the form of a relatively thick, endless, felt band or belt passing over a cylindrical bed roll 16 to provide a yielding sur face on the bed roll to take the thrust of the tool 2 on the work. Asshown, the-bed roll 16 is secured to a shaft 20- supported in bearings 22 in a swing frame 2% pivoted upon a rod 26 carried by the frame 8, I

The upper section of each bearing 22 mayv be removably secured to the lower hearing by a bolt 27 and if desired'these bolts may be relied upon to clamp the shaft 20 and the bed roll 16 against rotation, as will befui ther explained. A bell crank lever. 30,.co1istituting a treadle, is connected to the swing frame 24 by a rod 28 and, against the resistance of a spring 32, it may be moved by'the operator to present the work sustained by the bolster 14 to the bufiing roll 2. A rod 34: carried by the frame 8 constitutes a stop to limit the movement of the swing frame and of the bolster away from the bufling roll under the influence of the spring 82. I Screws 36 threaded through a bracket 38 secured to the swing frame 24 are arranged to engage the forward side of rod 34 and provide adjustable means for determining the inner limit of the movement of the work supporting structure, the adjustment of the screws 86 preferably being such '0 rat the bolster can not be brought into engagement with the'buifin-g roll, as for ex ample, when there is no work between tn bolster and the roll. A bracket 40 is secured to theswing frame 24, or it'may be integral with it, at either-end of the bed roll. An upright link 42 is pivoted to each bracket and carries atits upper end an adjustable screw 46 threaded through the link and having a. tapered inner end to en.- gage a corresponding recess in the axis, and

at each end, of the tension roll 18. Adjusting screws 48 threaded through lugs upon the links 42 engage projections of the brackets 40 and provide means for adjusting the position of the tension roll 18 relatively to the bed roll 16 and consequently for adjusting the tension of the band 14. A protecting apron or cover 52 extends over the upper run of the band 14 and is secured by bolts 54 to the upper sections of bearings 22 and the projections 50. r

In the use of the machine, the operator may conveniently stand at the front of the ma chine, which is at the left as shown in the drawings, holding in his hands a piece of leather L to be buffed. He then introduces the lower end of thepiece L into'the space between .the bolster 14 and the bu'ffing roll ing position.

by reason'of the fact that .of the type shown provides a relatively large 2, letting it rest against the bolster, while the parts are in the relative position shown in Fig. 1. The operator then depresses'the treadle 30, to bring the" work into cont-act with the abrasive surface 4, and allows the leather to be fed slowly downward between the rapidly rotating buffing roll 2 and the work support 14, in the usual, well-known manner. Accordingly, after approximately one-half of the length of the piece of work has been buffed, the operator releases the treadle 80, the swing frame retracting and carrying the leather away from the buffing roll, whereupon the leather is lifted and also shifted laterally by the operator to bring a fresh portion thereof opposite the buiiing' roll and the. operation is repeated until substantially the lower halfof the leather has been completely buffed. Thereupon it is turned end for end and the other half is buffed. From time to time the tension of the band 14 is adjusted by thumb screws 48 to secure the desired degree of tension. Under some conditions and with certain kinds of leather, the bed roll is clamped against rotation, as already suggested, but even then there may be a slight movement or creeping of the bolster 14 over the bed roll 16 in a clockwise direction as the work is fed downward, with the result that afresh portion of the bolster is continually being presented in work support- However, the operator may also readily shift the bolster over the-bed roll by the use of his hands between operations on successive pieces of work. Under other circumstances,'the bed roll 16 or its shaft 20 may be mounted for free rotation so that the working portion of the bolster will be shifted more rapidly.

I It will be noted that, because the bolster is mounted to move freely over its supper rolls and is not cemented to the bed roh can readily be removed and replaced, when it becomes worn, by removing the bolts 2? and 54 and loosening the screws 46; However,

supporting surface,'renewal of the band is an endless band required at comparatively infrequent inter-- vals. Moreover, by maintaining the proper tension of the band by means of adjusting roll at relativel hi 'h s need. a swin frame pivoted in said supporting frame, a bed roll and a tension roll carried by the swing frame, an endless felt band supported by said bed and tension rolls, a protecting apron'above said band, means whereby the bed and tension rolls may be relatively adjusted to vary the tension of the band, and means whereby the swing frame may be moved toward the buffing roll to present a piece of leather resting against said band to the-actionof the bufiing roll.

2. A leather buffing machine having, in combination, a bufiing roll, means for rotating said roll,'a bed roll, a tension roll, and

an endless felt band passing over the bed.

and tension rolls, the latter with the band being all movable as a unit toward and from the buffing roll, said band providing a yielding surface on the bed roll to back .the work along the lineof application of the bulling roll thereto, and means whereby the tension roll and bed roll maybe relatively adjusted to maintain the desired tension in the band.

3. A leather buffing machine having, in combination, a bufiing member, means for operating the buffing member, a bed roll, a felt band passing over the bed roll to present a work supporting surface for cooperation with the bufling member, and bedroll serving as a backing for the band along the line of application of the butling member to a piece of work between the band and the bulfing member, and means spaced from the bed roll for tensioning the feltband.

4. A leather buffing machine having, in combination, a buffing roll, means for rotating said roll, a bed roll, a member spaced from the bed roll, an endless felt band passing over the bed roll and over the'member, pivoted links for supporting said member, and means for adjusting each of the links abouts its pivotal axis to tension the felt band.

5. A leather buffing machine having, in combination, a bufling roll, means for rotating said. roll, and a work support relatively mov- "able toward and from said roll and comprising two supporting rolls and an endless felt band carried by said supporting-rolls,-the felt band being backed by one of the rolls along the line of application of the buffing roll to Work passing between the band and the bulling roll.

6. In a leather Working machine, a rotary tool, means through Which a piece of leather may be presented to the action of said tool comprising an endless band of material having a yielding surface to support the leather against the thrust of the tool, and a pair of supports for said hand, one of said supports being arranged to back the band along the line of application of the tool to a piece of leather passing between the band and the tool.

In testimony whereof I have signed my name to this" specification. H

OSKAR BOTTGER. 

